# first step:
# yum install ntp
# test cmd:
# date -s "2015-10-25 15:00:00"
import os

NTP_SERVER = "pool.ntp.org"
# ntp should be installed
cmd_ntp = "ntpdate " + NTP_SERVER
# sync to bios
cmd_hwclock = "hwclock -w"

os.system(cmd_ntp + " ; " + cmd_hwclock)
